GTA IV modding

Hey guys i got a problem kind of i just went and bought GTA IV and ive installed it and played it for like 10mins now the only reason i bought it was too mod it so i tried too and failed i tried following tutorials and what not and it failed i dont know what version im running on wich sint good at all because i need too know what stuff to download sop im looking for someone who has modded the game and knows something about it and stuff i would like if somone could maby teamview with me and just do it for me
its not that im lazy but i dont wanna mess things up thanks alot guys BTW the mod i want is police persuit mod thanks.

~Craig

-removed the link-
(I think I can get banned for linking to the file)

Police Pursuit mod needs 1.0.7.0 patch.

Also, you must install scripthook and an asi loader.